Yellow Leaves on Cannabis: A Diagnostic Walkthrough
By The Budometry TeamPublished Updated
Yellow leaves are a symptom with a dozen causes. Location, pattern, and timing narrow it down in under a minute.
Part of our pillar guide: Plant Training, Pests and Troubleshooting
Bottom leaves, uniform yellow, whole plant pale
Nitrogen deficiency. Common in mid-veg when a plant outgrows its soil charge. Increase your nitrogen-heavy base feed.
Bottom leaves, yellow between green veins
Magnesium deficiency, extremely common with RO water. Add Cal-Mag and verify pH is in range.
New top growth yellow or distorted
An immobile nutrient — calcium, iron, sulfur — or a pH lockout. Check and correct pH before adding anything.
Yellow with droop and wet, heavy soil
Overwatering. Stop watering and let the pot dry back to light before feeding again.
Late flower, gradual yellowing everywhere
Normal senescence. The plant is reclaiming nutrients from leaves to finish flowers. This is expected and healthy in the last two or three weeks.
Frequently asked questions
- Should I remove yellow leaves?
- Only once they are mostly yellow and detach easily. Removing partially yellow leaves takes nutrients away from the plant.
The full guide on this topic
Plant Training, Pests and Troubleshooting
Topping, LST and SCROG explained, plus how to identify and stop spider mites, fungus gnats and powdery mildew, and how to read leaf symptoms correctly.